I blast everything inside and out with SAND. Of course its #1 Silica sand, about the consistency of fine sugar or flour. I run the pressure way down to 40psi. Everything is nice and clean without doing any damage to anything. If you use 1000 grit sandpaper and it smooths the work to a perfect shine, you have nothing to worry about. I can't be bothered with different grits of anything in my blast cabinet. I use it almost every day. By changing pressure I can get the super fine jobs done, or with 120psi I can get the harder jobs done. The only complaint I have with my system is, it isn't aggressive enough when trying to cut some of the older lead paints. I use it anyway, just takes a long time.
To clean, high pressure air, then a naptha based cleaner (PPG's DX-330). Like brandy new! For the smaller orifices, I use a HVLP paint gun cleaning kit that has those cleaning tools. Understand though, the smallest orifice in a carb, you can pour the sand I use into. Not large enough to clog it. That is worst case scenario.. example.. a carb that has been sitting in a salvage yard for 30 years. If the carb is in use or has been recently, I would gently blast the outside and kerosene (small parts washer) clean the inside. Providing the gold plating is compromised of course. (It almost always is).
So Allen, if you don't want Silica Sand, get something with a similar consistency, then use pressure changes to change your strength. You will be good to go!
